Venoco shareholders have approved CEO Tim Marquez’s bid to take the company private despite the fact that he has yet to give details on how he would gather the nearly $400 million in financing to close the deal.

After the June 5 vote, Marquez has until June 12 to show a special committee of the Venoco’s board how he would gather financing for the deal and close it or else request an extension, which the company has said it is likely to grant. An extension could be a sign that financiers are skeptical that the timing is right for a going-private transaction when oil prices are slipping.

In August 2011, Marquez, a former petroleum engineer who founded Venoco with his savings and credit cards, offered to take Venoco private at $12.50 a share, a nearly 30 percent premium to the firm’s recent trading prices. Marquez owns about 51 percent of the firm, whose headquarters have moved to Denver while a large workforce remains in the Tri-Counties. The deal fetched a majority of the minority shareholder votes to pass.

Marquez’s bid has sparked controversy at every step as investors questioned whether it benefited them or Marquez. Angry shareholders insisted that Marquez had timed his deal when the stock was trading at unusually low prices, and analysts pointed out that the deal valued the company at about $770 million, which was less than the price of the assets on the company’s balance sheet. Shareholder lawsuits ensued.

To keep in line with shareholder rights rules, Venoco created a special committee on its board of directors to negotiate with Marquez, who is also a director. After four months of wrangling in which Marquez lowered his bid and then raised it back to his original offer, the board and Marquez both agreed to the $12.50 a share price.

In public filings, the company said Marquez will need $385 million to $400 million to close the deal. But shareholders have no details on how that financing will be arranged. Venoco has agreed to reimburse Marquez up to $4 million in costs if the deal doesn’t go through by Oct. 16.

The going-private offer takes place against the background of Marquez’s ambitions for the so-called Monterey Shale, a rock formation several miles beneath the surface inland in California. Much of the $100 million that Marquez raised in 2007 by selling almost half of the firm on the public markets has gone toward gobbling up acreage, making Venoco one of the largest holders of it, alongside larger firms such as Occidental Petroleum.

As of yet, the Monterey Shale has not been cracked in a cost-effective way. The acquisitions were a large bet that Marquez, with his engineering background, could find a way to retrieve the deep-buried resources. But falling oil prices tied to weak global demand spurred by Europe’s economic woes has caused investors to question Marquez’s strategy.

[Correction: Due to a Business Times misinterpretation of the legal language in Venoco’s merger agreement, this story incorrectly stated that Marquez had “quietly” secured an extension to provide financing details for the deal. In fact, Marquez has until June 12 to provide those details, and the company has signaled it will disclose whether it grants him an extension. The article also misstated the amount that Marquez might be reimbursed if the deal does not close.]